1. Field of the Invention
The invention relates to a glove which is adapted to inhibit or prevent carpal tunnel syndrome. Particularly, the present invention relates to a glove assembly which inhibits or prevents carpal tunnel syndrome while providing increased flexibility and ease of movement to the wearer of the glove assembly.
2. Description of Related Art
Carpal tunnel syndrome is a common condition which occurs due to the compression of the median nerve. It is sometimes referred to as median compression neuropathy within the carpal canal. Carpal tunnel syndrome is a particular problem for workers in industries which require manual operations with hand held implements or tools or in office situations wherein a worker may be required to spend several hours a day resting their hands on a typewriter or computer terminal and may also be sports related.
Carpal tunnel syndrome is a clinical syndrome characterized by numbness, weakness, paraesthesia or atrophy in the territory of the median nerve distal to the course through the carpal tunnel in the wrist. The transverse carpal ligament forms over the median nerve and may compress the median nerve as a result of pressure on the hand, producing the above described symptoms. Traumatic injury is exacerbated because of the narrowness of the carpal canal. There is no opportunity for the nerve to be displaced away from any compressive forces. Compressive injury can be exacerbated by the development of edema in the tissues within the canal, which because of the relatively fixed size, can cause added injury due to compression of the nerve within the canal. An additional component of the injury is associated with friction between the nerve and the adjacent tendons caused by repetitive motions (injury) which may be worsened by compression and further reduce the available space within the canal.
Two types of injury can occur due to compression of the median nerve. The milder, earlier form is a demyelination of the median nerve within the canal. This type of demyelination occurs early in the course of compressive injury. However, this form of injury is also more readily reversible and recovery can occur in four to six weeks after compression is relieved. This form of injury can cause motor weakness due to acute conduction block in the nerve, however, this weakness is readily reversible.
The second major form of injury includes damage to the axons themselves. This form of injury occurs in more severe or prolonged cases and has more significant implications in that it often leads to motor weakness. This type of motor weakness tends to be poorly reversible and often irreversible. Loss of strength in the thenar muscles can lead to major disabilities due to the loss of ability to grip or perform fine dexterous manipulations. This second form of injury is generally seen in long-standing cases, many of which, first clinically manifest in a manner suggestive of the demyelinating form.
If the median nerve is injured at the wrist, as by wounds or by a dislocation of the lunate bone, sensation may be lost in the skin on the front of the index finger and adjacent part of the thumb and over the back of the distal phalanges of the thumb, index finger, and middle fingers, and is diminished over a large area. The brunt of the paralysis falls on the muscles of the thenar eminence which, in time, flattens and wastes.
Treatment of carpal tunnel syndrome varies according to the severity of the condition. Severe conditions usually require hand surgery to sever the transverse carpal ligament, whereas in less severe cases, a splint may be utilized to immobilize the wrist.
In order to prevent or inhibit a person from development carpal tunnel syndrome, a number of gloves and wrist braces have been designed. One such glove is disclosed in U.S. Pat. No. 4,850,341 to Fabry et al., issued Jul. 25, 1989, which discloses a glove for inhibiting or preventing carpal tunnel syndrome which includes a pad configured to cover and protect the median nerve of the wearer's hand. The problem with such a device is that the pad is placed directly over the median nerve and, therefore, transmits pressure from the external source to the carpal tunnel ligament. With this type of relationship, repetitive finger movements can increase the potential for frictional injury. Additionally, having a pad oriented directly over the median nerve, allows for the direct transmission of pressure to the median nerve.
In order to overcome the problems associated with the type of glove disclosed in the Fabry et al. patent, a pad design was disclosed in U.S. Pat. No. 5,031,640 to applicant, issued Jul. 16, 1991 and incorporated herein by reference, which eliminates the continuous pressure applied directly over the median nerve by providing a recess over the median nerve in a support pad thereby preventing or eliminating carpal tunnel syndrome. This type of design has proven to be very effective in inhibiting or preventing carpal tunnel syndrome. However, it would be advantageous and desirable to incorporate into the pad which eliminated continuous pressure directly over the median nerve, a means of improving the flexibility and ease of movement to the wearer of the glove containing such a pad.